What is flakka (aka gravel) and why is it more dangerous than cocaine?

(Credit: DEA) Flakka is a man-made drug causes a high similar to cocaine. It is also called "gravel" because of its white crystal chunks that have been compared to aquarium gravel.

By Carina Storrs Special to CNN

(CNN) -- It goes by the name flakka. In some parts of the country, it is also called "gravel" because of its white crystal chunks that have been compared to aquarium gravel.

The man-made drug causes a high similar to cocaine. But like "bath salts," a group of related synthetic drugs that were banned in 2012, flakka has the potential to be much more dangerous than cocaine.

"It's so difficult to control the exact dose [of flakka]," said Jim Hall, a drug abuse epidemiologist at Nova Southeastern University in Fort Lauderdale, Florida. "Just a little bit of difference in how much is consumed can be the difference between getting high and dying. It's that critical."

A small overdose of the drug, which can be smoked, injected or injected, can lead to a range of extreme symptoms: "excited delirium," as experts call it, marked by violent behavior; spikes in body temperature (105 degrees and higher, Hall said); paranoia. Probably what has brought flakka the most attention is that it gives users what feels like the strength and fury of the Incredible Hulk.

Flakka stories are starting to pile up. A man in South Florida who broke down the hurricane-proof doors of a police department admitted to being on flakka. A girl in Melbourne, Florida, ran through the street screaming that she was Satan while on a flakka trip. Authorities in the state are warning people about the dangers of the drug.

Florida seems to be particularly hard hit by flakka overdoses.

Hall said that there are about three or four hospitalizations a day in Broward County in South Florida, and more on weekends. It is unclear why the Sunshine State is a hotbed for flakka abuse; "it's a major question in our community," Hall said.

Cases have also been reported in Alabama, Mississippi and New Jersey.

Flakka, which gets its name from Spanish slang for a beautiful woman ("la flaca"), contains a chemical that is a close cousin to MDPV, a key ingredient in "bath salts." These chemicals bind and thwart molecules on the surface of neurons that normally keep the levels of mood-regulating neurotransmitters, dopamine and serotonin, in check. The result is to "flood the brain" with these chemicals, Hall said. Cocaine and methamphetamine have similar modes of action in the brain, but the chemicals in flakka have longer-lasting effects, Hall said.

Although a typical flakka high can last one to several hours, it is possible that the neurological effects can be permanent. Not only does the drug sit on neurons, it could also destroy them, Hall said. And because flakka, like bath salts, hang around in the brain for longer than cocaine, the extent of the destruction could be greater.

Another serious, potentially lingering side effect of flakka is the effect on kidneys. The drug can cause muscles to break down, as a result of hyperthermia, taking a toll on kidneys. Experts worry that some survivors of flakka overdoses may be on dialysis for the rest of their life.

Like most synthetic drugs, the bulk of flakka seems to come from China and is either sold over the Internet or through gas stations or other dealers. A dose can go for $3 to $5, which makes it a cheap alternative to cocaine. Dealers often target young and poor people and also try to enlist homeless people to buy and sell, Hall said. These are "people who are already disadvantaged in terms of chronic disease and access to health care," he added.

It is unclear at this point whether flakka is more dangerous than the "bath salts" that came before it. But it does have one advantage over its predecessor: it has not been banned -- yet.

"Flakka largely emerged as a replacement to MDVP [in 'bath salts']," said Lucas Watterson, a postdoctoral researcher at Temple University School of Medicine Center for Substance Abuse Research.

Although the Drug Enforcement Administration has placed a temporary ban on flakka, drug makers can work around this ban, such as by sticking a "not for human consumption" label on the drug, Watterson said. It will probably take several years to get the data necessary to put a federal ban on flakka, he added. And a ban can be effective, at least in discouraging potential users.

"The problem is when one of these drugs is banned or illegal, the drug manufacturer responds by producing a number of different alternatives," Watterson said. "It's sort of a flavor of the month."